An image forming apparatus includes a main assembly and a drawer unit. The drawer unit includes a photosensitive drum, an optical print head, first to third wall portions and a relay substrate. The main assembly includes a first facing portion, a second facing portion and a main assembly substrate. The relay substrate and the main assembly substrate are connected by a cable folded back at the rear of the third wall portion. A distance between a portion of the cable before being folded back and a portion of the cable after being folded back is longer than a distance, with respect to a longitudinal direction of the optical print head, between the first or second wall portion on which the relay substrate is provided and the first or second facing portion facing the first or second wall portion on which the relay substrate is provided.
|
1. An image forming apparatus comprising:
a main assembly; and
a drawer unit movable between a mounted position where said drawer unit is mounted in said main assembly and a drawn-out position where said drawer unit is drawn out of the mounted position,
wherein said drawer unit comprises:
a rotatable photosensitive drum,
an optical print head including a light emitting element configured to expose said photosensitive drum to light,
first, second and third wall portions, wherein said first wall portion supports one end side of said optical print head with respect to a longitudinal direction of said optical print head, said second wall portion supports the other end side of said optical print head with respect to the longitudinal direction, and said third wall portion is continuously formed between an upstream end portion of said first wall portion and an upstream end portion of said second wall portion with respect to a drawing out direction of said drawer unit from the mounted position toward the drawn-out position to form a wall portion in cooperation with said first wall portion and said second wall portion, and
a relay substrate provided on either one of an outer surface of said first wall portion and an outer surface of said second wall portion with respect to the longitudinal direction and configured to relay a signal for driving said optical print head,
wherein said main assembly comprises:
a first facing portion provided on a side opposite from a side facing said second wall portion and configured to face said first wall portion,
a second facing portion provided on a side opposite from a side facing said first wall portion and configured to face said second wall portion, and
a main assembly substrate configured to generate a driving signal for driving said light emitting element,
wherein said relay substrate and said main assembly substrate are connected by a cable, and when said drawer unit is in the mounted position, said cable extends from said relay substrate in an opposite direction to the drawing-out direction and is folded back in the drawing-out direction on a side downstream of said third wall portion with respect to the opposite direction and then is connected to said main assembly substrate through an opening provided in one of said first facing portion and said second facing portion, facing said relay substrate on a side downstream of said third wall portion with respect to the drawing-out direction, and
wherein said cable folded back includes portions with respect to the longitudinal direction on a side upstream with respect to the drawing-out direction, wherein a distance between said portion of said cable before being folded back and said portion of said cable after being folded back is longer than a distance, with respect to the longitudinal direction, between said first or second wall portion on which said relay substrate is provided and said first or second facing portion facing said first or second wall portion on which said relay substrate is provided.
2. An image forming apparatus according to
wherein said connector projects toward a side upstream of said third wall portion with respect to the drawing-out direction on a side where said connector is connected to said cable.
3. An image forming apparatus according to
4. An image forming apparatus according to
wherein said fixing member is provided on said third wall portion.
5. An image forming apparatus according to
6. An image forming apparatus according to
8. An image forming apparatus according to
9. An image forming apparatus according to
wherein said optical print heads are arranged in the drawing-out direction.
10. An image forming apparatus according to
11. An image forming apparatus according to
|
The present invention relates to an image forming apparatus for forming an image by using an optical print head.
In a printer which is an image forming apparatus of the electrophotographic type, the following light exposure type has been known in general. That is, a light exposure type in which a photosensitive drum is exposed to light by using a light exposure head such as a light emitting diode (LED) or an organic electroluminescence (EL) element and a latent image is formed has been known in general. The exposure head includes a light emitting element array arranged in a longitudinal direction of the photosensitive drum and a rod lens array for forming an image on the photosensitive drum with light from the light emitting element array. As regards the LED or the organic EL element, a constitution having a surface (planar) emitting shape such that an irradiation direction of light from a light emitting surface is the same direction as the rod lens array has been known. Here, a length of the light emitting element array is determined depending on a width of an image forming region on the photosensitive drum, and an interval between light emitting elements is determined depending on resolution of the printer. For example, in the case of the printer of 1200 dpi in resolution, a pixel interval is 21.16 μm, and therefore, the interval between the light emitting elements is also an interval corresponding to 21.16 μm. In the printer using such an exposure head, compared with a printer of a laser scanning type in which the photosensitive drum is scanned with a laser beam deflected by a rotatable polygonal mirror, the number of component parts is small, and therefore, downsizing and cost reduction of the printer are easy. Further, in the printer using the exposure head, noise generating by rotation of the rotatable polygonal mirror is reduced.
Further, in the image forming apparatus of the electrophotographic type, a constitution in which an image forming unit accommodating an image forming portion such as a developing device, a photosensitive drum and the like is capable of being drawn out to an outside of the image forming apparatus in order to perform exchange of consumables such as toner and the photosensitive drum and to perform a maintenance operation is employed. The drawing-out of the image forming unit is enabled, so that access to respective devices accommodated in the image forming unit is made easy and thus the maintenance operation is facilitated.
Parts (a) and (b) of
The flat cable 520 connecting the image controller 503 and the LED emission controller 504 is slid with drawing-out and insertion of the LED emission controller 504 in a bent state. In general, the flat cable 520 causes a difference in durability depending on a bending radius R thereof. For example, in sliding in the bending radius R of 10 mm, durability of 30,000 times or more is obtained, while in sliding in the bending radius R of 5 mm, durability is 10,000 times, and in sliding in the bending radius R of 3 mm, durability of only about 1,000 times is obtained. That is, the flat cable 520 lowers in durability with a decreasing bending radius R. In the constitution of JP-A 2012-144019, as shown in part (a) of
According to an aspect of the present invention, there is provided an image forming apparatus comprising: a main assembly; and a drawer unit movable between a mounted position where the drawer unit is mounted in the main assembly and a drawn-out position where the drawer unit is drawn out of the mounted position, wherein the drawer unit comprises a rotatable photosensitive drum, an optical print head including a light emitting element configured to expose the photosensitive drum to light, first, second and third wall portions, wherein the first wall portion supports one end side of the optical print head with respect to a longitudinal direction of the optical print head, the second wall portion supports the other end side of the optical print head with respect to the longitudinal direction, and the third wall portion is continuously formed between an upstream end portion of the first wall portion and an upstream end portion of the second wall portion with respect to a drawing out direction of the drawer unit from the mounted position toward the drawn-out position to form a wall portion in cooperation with the first wall portion and the second wall portion, and a relay substrate provided on either one of an outer surface of the first wall portion and an outer surface of the second wall portion with respect to the longitudinal direction and configured to relay a signal for driving the optical print head, wherein the main assembly comprises a first facing portion provided on a side opposite from a side facing the second wall portion and configured to face the first wall portion, a second facing portion provided on a side opposite from a side facing the first wall portion and configured to face the second wall portion, and a main assembly substrate configured to generate a driving signal for driving the light emitting element,
wherein the relay substrate and the main assembly substrate are connected by a cable, and when the drawer unit is in the mounted position, the cable extends from the relay substrate in an opposite direction to the drawing-out direction and is folded back in the drawing-out direction on a side downstream of the third wall portion with respect to the opposite direction and then is connected to the main assembly substrate through an opening provided in one of the first facing portion and the second facing portion, facing the relay substrate on a side downstream of the third wall portion with respect to the drawing-out direction, and wherein the cable folded back includes portions with respect to the longitudinal direction on a side upstream with respect to the drawing-out direction, wherein a distance between the portion of the cable before being folded back and the portion of the cable after being folded back is longer than a distance, with respect to the longitudinal direction, between the first or second wall portion on which the relay substrate is provided and the first or second facing portion facing the first or second wall portion on which the relay substrate is provided.
Further features of the present invention will become apparent from the following description of exemplary embodiments with reference to the attached drawings.
Parts (a) to (c) of
Part (a) of
Parts (a) and (b) of
Parts (a) and (b) of
Part (a) of
Parts (a) and (b) of
In the following, embodiments of the present invention will be specifically described with reference to the drawings.
[Structure of Image Forming Apparatus]
Part (a) of
The casing 400 is a unit which includes therein four process cartridges (image forming portion) of different toner colors of yellow (Y), magenta (M), cyan (C) and black (K) and which is capable of being drawn out of and mounted in the printer 100. The casing 400 includes an open surface which is open upward and an outer periphery thereof is surrounded by side walls. The respective process cartridges have the same constitution, and each process cartridge is constituted by a photosensitive drum 102 rotatable relative to a main assembly (image forming apparatus main assembly) of the printer 100, a charging device 402 and a developing device 403. Further, the exposure head 106 is provided opposed to the photosensitive drum 102 of each process cartridge. One end side of the exposure head 106 with respect to a rotational axis direction of the photosensitive drum 102 is supported by a side wall portion (first wall portion) of the casing 400. Further, also the other side of the exposure head 106 with respect to the rotational axis direction of the photosensitive drum 102 is supported by a side wall portion (second wall portion) of the casing 400. Further, the respective process cartridges are also supported by the two side wall portions supporting the exposure heads 106 and are capable of being accommodated between the two side wall portions.
Incidentally, suffixes Y, M, C and K of reference numerals represent members of the process cartridges for yellow, magenta, cyan and black, respectively. In the following, description of the suffixes will be omitted except for the case where description of a specific process cartridge is made.
When image formation is started, in each of the process cartridges, the charging device 402 electrically charges uniformly a surface of the photosensitive drum 102 rotating an arrow direction (counterclockwise direction) in the figure. Then, the exposure head 106 which is an optical print head causes a chip surface of an LED arrow to emit light depending on the irradiation data from an LED control substrate 501 described later, and the emitted light is condensed at the surface of the photosensitive drum 102 by a rod lens array, so that an electrostatic latent image is formed. The developing device 403 deposits the toner on the electrostatic latent image formed on the photosensitive drum 102, and thus develops the electrostatic latent image with the toner, so that a toner image is formed. Here, the exposure head 106 is an elongated head. The exposure head 106 is disposed so that a longitudinal direction of the exposure head 106 and a rotational axis direction of the photosensitive drum 102 coincide with each other. However, “coincide with each other” referred to herein does not mean that the longitudinal direction of the exposure head 106 and the rotational axis direction of the photosensitive drum 102 are strictly parallel to each other. It permits that these directions are somewhat inclined relative to each other due to component part tolerance.
A transfer belt 406 is an endless belt which is provided between a sheet (paper) feeding cassette 408 and the respective photosensitive drums 102 and which is rotatable in an arrow direction (clockwise direction) in the figure while being stretched by a plurality of rollers. Further, at positions facing the photosensitive drums 102, transfer rollers are provided inside the transfer belt 406 so as to sandwich the transfer belt 406 between the transfer rollers and the photosensitive drums 102. The toner images formed on the photosensitive drums 102 of the process cartridges are transferred onto the transfer belt 406 contacted to the photosensitive drums 102 by the transfer rollers, whereby the respective color toner images are superposed on the transfer belt 406, so that a full-color toner image is formed.
On the other hand, in synchronism with the image formation of the respective process cartridges of the casing 400, a sheet S is fed from the sheet feeding cassette 408 of the sheet feeding/conveying portion 405 and is conveyed toward a secondary transfer device 407. In the secondary transfer device 407, the toner images on the transfer belt 406 are transferred onto the fed sheet S. Then, the sheet S on which the toner images are transferred is conveyed to a fixing portion 404 by a conveying belt 412. In the fixing portion 404, unfixed toner images on the conveyed sheet S are pressed and heated, so that the toner images are fixed on the sheet S. Thereafter, the sheet S is conveyed in a conveying passage and is discharged onto a discharge tray 409.
Part (b) of
Part (c) of
[Structure of Light Exposure Head]
Next, the exposure head 106 for performing the exposure of the photosensitive drum 102 to light will be described using
As shown in part (b) of
[Structure of Surface Emitting Element Array Element Group]
As shown in part (a) of
Part (c) of
Further, as shown in part (b) of
[Control Constitution of Main Assembly Substrate Control Substrate and Light Exposure Head]
Further, the LED control substrate 101, which is a relay substrate, includes an LED emission controller 504. The LED emission controller 504 receives the image data outputted from the image controller 503 of the main assembly substrate 500, and on the basis of the received image data, generates irradiation data corresponding to the respective surface light emitting elements of the surface emitting element array chips 1 to 29 mounted on the exposure heads 106. The image data from the image controller 503 includes color information on whether or not the image data is for which color of yellow (Y), magenta (M), cyan (C) and black (K). On the basis of the color information, the LED emission controller 504 outputs the irradiation data of the photosensitive drums 102 corresponding to the respective colors to the driving substrates 202 of the exposure heads 106 on which the surface emitting element array chips for the respective colors are mounted. The driving portions 303a and 303b mounted on each of the driving substrates 202 of the exposure heads 106 carry out turning-on control of the surface light emitting elements on the basis of the irradiation data received from the LED emission controller 504, so that the photosensitive drums 102 are exposed to light.
Further, the LED control substrate 501 also has the function as the relay substrate for electrically connecting the main assembly substrate 500 and the driving substrates 202 of the exposure heads 106. Specifically, as shown in
[Capable Connection Structure Between Main Assembly Substrate and LED Control Substrate]
The LED control substrate 501 is provided on a side wall (on the front side of the drawing sheet in the figure) at a “RR” end portion of the side wall. On the other hand, the main assembly substrate 500 is disposed on the guiding member 506L, but compared with the LED control substrate 501, the main assembly substrate 500 is disposed at a position close to the bottom of the casing of the printer 100. Further, the main assembly substrate 500 includes a connector 540 for connecting the cable 520, and the LED control substrate 501 includes a connector 530 for connecting the cable 520.
Next, connection between the main assembly substrate 500 and the LED control substrate 501 by the cable 520 which is the flat cable will be described. The cable 520 connected to the connector 540 of the apparatus main assembly substrate 500 extends in the “RR” direction in the figure from the connector 540 of the main assembly substrate 500, and thereafter is folded back at a fold-back point 522, and then extends in the “U” direction in the figure. Thereafter, the cable 520 is folded back at a fold-back point 523 and then extends in the “RR” direction. Thereafter, the cable 520 extended in the “RR” direction is, as shown in
[Shape of Cable Connecting Main Assembly Substrate and LED Control Substrate]
Parts (a) and (b) of
In part (a) of
When a position where the casing 400 is mounted in the printer 100 is a mounted position and a position where the casing 400 is drawn out of the printer 100 is a drawn-out position, a direction in which the casing 400 moves from the mounted position toward the drawn-out position is a drawing-out direction. The drawn-out position is a position where the casing 400 is drawn out to the extent that a user is capable of performing an exchanging operation of the process cartridge. Specifically, a position where the casing 400 is drawn out of the printer 100 through an opening provided in the printer 100 and the exposure head 106Y for yellow (Y) is exposed through the opening and thus the user has access to the exposure head 106Y is defined as the drawn-out position. The third wall portion of the casing 400 is continuous to both the upstream end portion of the first wall portion and the upstream end portion of the second wall portion with respect to the drawing-out direction of the casing 400 from the printer 100. Thus, the third wall portion forms a wall surface of the casing 400 in cooperation with the first wall portion and the second wall portion. Incidentally, the above-described connector 530 projects further toward the upstream side with respect to the drawing-out direction than the third wall portion projects, on a side where the connector 530 is connected to the cable 520. Further, as shown in parts (a) and (b) of
Further, in this embodiment, the LED control substrate 501 is provided on the side wall 400SL at the “RR”-side end portion. Between the casing 400 and the casing of the printer 100, the guiding members 506, which are fixed to the casing of the printer 100, for guiding drawing-out and accommodation of the casing 400 are provided. The guiding members 106 which are examples of facing portions are a pair of guiding members provided on the “R” and “L” sides in the figure, in which the guiding member 506 on the “R” side is a guiding member 506R and the guiding member 506 on the “L” side is the guiding member 506L. A first facing portion corresponds to the guiding member 506R, and a second facing portion corresponds to the guiding member 506L.
In
The cable 520 passes through the opening 507 and connects the connector 540 of the main assembly substrate 500 and the connector 530 of the LED control substrate 501. Incidentally, in the case where the casing 400 is drawn out of and inserted into the printer 400, the opening is provided at a position where a distance from the opening 507 to the LED control substrate 501 is the same. For that reason, the position of the opening 507 is disposed further toward the “RR” side in the figure than the apparatus main assembly substrate 500 is, and in other words, when the casing 400 is in the mounted position, the opening 507 is formed in the guiding member 506L on a side downstream of the third wall portion with respect to the drawing-out direction. Further, the position of the opening 507 is disposed further toward the “FR” side in the figure than the LED control substrate 501 is. Further, the position of the guiding member 506L in the figure is further toward the “RR” side than the position of the side wall 400R of the casing 400 is. Further, the LED control substrate 501 and the exposure heads 106 (106Y, 106M, 106C, 106K) are connected with each other via the cables 505 (505Y, 505M, 505C, 505K), respectively.
In part (a) of
Thus, when the casing 400 is in the mounted position, a width of the cable with respect to the left-right direction (longitudinal direction of the exposure head 106) on the side upstream of the side wall 400R with respect to the drawing-out direction is wider (larger) than a distance between the side wall 400SL and the guiding member 506L. This is because stiffness of the cable 520 presses and extends the folded-back cable 520. Thus, it is possible to suppress that a load is exerted on the cable 520 more than necessary by the mounting and drawing-out operation of the casing 400.
On the other hand, part (b) of
As described above, by drawing-out of the casing 400 from the printer 100 and inserting the casing 400 into the printer 100, the cable 520 is bent, so that a load is applied to the cable 520. In general, the flat cable used as the cable 520 has a durable lifetime characteristic against bending, and when the flat cable is bent not less than the number of times of the lifetime, the flat cable causes breakage thereof in some cases. For that reason, the flat cable used as the cable 520 should be selected on the basis of the number of times of durability satisfying the number of times of drawing-out and insertion of the casing 400. Further, bending durability of the flat cable becomes long in terms of durability lifetime when the bending radius of the curved portion shown in part (a) of
[Shape of Cable in Case that LED Control Substrate is Provided at Rear Portion of Casing]
In
Thus, also in the case where the LED control substrate 501 is provided on the side wall 400R of the casing 400, the position of the center 520C of the arcuate curved portion drawn by the cable 520 is similar to that in the case of part (a) of
[Other Shapes of Cable Connecting Main Assembly Substrate and LED Control Substrate]
By providing the cable 520 with the fold 520B, the bending radius of the cable 520 can be made larger, but on the other hand, when the casing 400 is drawn out of and inserted into the printer 100, the fold 520B provided to the cable 520 is repetitively bent. For that reason, there is an increasing possibility that the cable 520 is broken. Therefore, parts (a) and (b) of
As described above, by employing the cable connection structure depending on an installation place of the LED control substrate 501, it is possible to compatibly realize maintenance of durability of the flat cable and downsizing of the image forming apparatus which are problems of a conventional cable connection structure. Incidentally, in the above-described embodiment, the apparatus main assembly substrate 500 was provided on the guiding member 506L provided on the “L” side of the printer 100, but the present invention is not limited to the guiding member 506L, and the main assembly substrate 500 may also be provided on the “R” side. In that case, an installation position of the LED control substrate 501 is, for example, on the side wall 400SR of the casing 400 or the end portion of the side wall 400R facing the guiding member 506R depending on the installation position of the main assembly substrate 500.
As described above, according to this embodiment, durability of the flat cable connecting the main assembly substrate and the LED control substrate can be prevented from lowering.
While the present invention has been described with reference to exemplary embodiments, it is to be understood that the invention is not limited to the disclosed exemplary embodiments. The scope of the following claims is to be accorded the broadest interpretation so as to encompass all such modifications and equivalent structures and functions.
This application claims the benefit of Japanese Patent Application No. 2018-202900 filed on Oct. 29, 2018, which is hereby incorporated by reference herein in its entirety.
Patent | Priority | Assignee | Title |
10955766, | Jun 07 2019 | Canon Kabushiki Kaisha | Image forming apparatus including optical scanning apparatus |
Patent | Priority | Assignee | Title |
10025257, | Dec 04 2007 | Brother Kogyo Kabushiki Kaisha | Image forming apparatus including a support frame and guide elements |
8311437, | Dec 04 2007 | Brother Kogyo Kabushiki Kaisha | Image forming apparatus with detachable cartridge |
8521061, | Dec 04 2007 | Brother Kogyo Kabushiki Kaisha | Image forming apparatus having support frame from which cartridges are detachable |
8594530, | Jan 14 2011 | Brother Kogyo Kabushiki Kaisha | Image forming apparatus |
8774673, | Jan 14 2011 | Brother Kogyo Kabushiki Kaisha | Image forming apparatus |
8831461, | Dec 04 2007 | Brother Kogyo Kabushiki Kaisha | Image forming apparatus having support frame from which cartridges are detachable |
9122238, | Jan 14 2011 | Brother Kogyo Kabushiki Kaisha | Image forming apparatus |
9176463, | Dec 04 2007 | Brother Kogyo Kabushiki Kaisha | Image forming apparatus having support frame from which cartridges are detachable |
JP2009157135, | |||
JP2012144019, | |||
JP2012145884, |
Executed on | Assignor | Assignee | Conveyance | Frame | Reel | Doc |
Oct 29 2019 | Canon Kabushiki Kaisha | (assignment on the face of the patent) | / | |||
Nov 13 2019 | KONDO, SHUNSAKU | Canon Kabushiki Kaisha | ASSIGNMENT OF ASSIGNORS INTEREST SEE DOCUMENT FOR DETAILS | 051416 | /0767 |
Date | Maintenance Fee Events |
Oct 29 2019 | BIG: Entity status set to Undiscounted (note the period is included in the code). |
Jan 24 2024 | M1551: Payment of Maintenance Fee, 4th Year, Large Entity. |
Date | Maintenance Schedule |
Aug 11 2023 | 4 years fee payment window open |
Feb 11 2024 | 6 months grace period start (w surcharge) |
Aug 11 2024 | patent expiry (for year 4) |
Aug 11 2026 | 2 years to revive unintentionally abandoned end. (for year 4) |
Aug 11 2027 | 8 years fee payment window open |
Feb 11 2028 | 6 months grace period start (w surcharge) |
Aug 11 2028 | patent expiry (for year 8) |
Aug 11 2030 | 2 years to revive unintentionally abandoned end. (for year 8) |
Aug 11 2031 | 12 years fee payment window open |
Feb 11 2032 | 6 months grace period start (w surcharge) |
Aug 11 2032 | patent expiry (for year 12) |
Aug 11 2034 | 2 years to revive unintentionally abandoned end. (for year 12) |